Improvement in heating-furnaces



` A 2 Sheets-Sheet 1. S. SMITH.

MATINci-Fummm. No-.172f,1 88. v ,Patentea Jan. 11,1876.

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-FU-RNAGE..

S. HEATING N. PETERS. FNQTO-U'YHOGRAPMER. WASNINGYOM, D C.

No.17Z188,'

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4but applicable to other classes of furnaces;

i grate, B, beneath which is an ash-pit, C, the

UNITED STATES PATENT OFFICE..

S1DNEY` SMITE, on WORCESTER, MASsncHU-SETTS.-

IMPROVEMENT IN HEATING-FuRNAcEs.`

Specification forming part of Letters Patent No. l 72,188,4 dated January 11, 1876; application filed May 31, 1875.

To all whom it may concern:

Be it known that I, SIDNEY SMiTH, of Worcester, in the county of Worcester and State of Massachusetts, have invented a new .[mprovement in Furnace; and I do hereby declare thefollwing, when taken in connection with the accompanying drawings and the letters of reference marked thereon, to be a full, clear, and exact description of the same, and which said drawings constitute part of this specification, and represent,'in-

Figure l, longitudinal central section; Fig. 2, vertical section on line w c; Fig. 3, vertical section on linezz; Figs. 4 and 5, detached views. l

This invention relates to an improvement in that class of furnaces for heating purposes in which the air is heated by passing back and forth through transverse lines, the said flues heated from the fire, the products of Which around the said transverse ues, to the escape,

and the invention consists'in the construction of the various parts, as fully hereinafter described.

A is the fire-box, the iire supported on a ash-pit closed by a door, D; E, the door closing the opening E' to the iirebox. Between the ash-pit door and the lire-opening, and on a level with the upper surface of the grate, is a third opening, F, closed by a door, F. At the inside of the front wall, and in this opening F, is an auxiliary door, G. (Shown in` Fig.4.) Beneath this door is an opening, a, uslf with the grate, the door held closed by latching into a notch, b, at the opposite side to Which itis hinged. The object of this door is to afford a convenient means for cleaning the grate, and to avoid the usual necessary shaking ofthe grate, and it is done by inserting the poker through the opening beneath the door G, and running it over the surface of the grate-that is, between the grate and the coal, which so agitates or disturbs the coal as to cause the ashes to be separated and fall through into the pit below,and if occasion requires the removal of clinkers or other foreign material, the door G may be opened, and such material beremoved without necessarily bringing it to the top of the fire, asis necessary in the common construction of furnaces. By this .construction the fire is much more perfectly and easily cleared than by any agitation of the grate r poking from below. H is the smoke or heating flue, which leads from the top of the tire-box down in a circuitous pas` sage to the exit H. 'This circuitous passage is preferably formed from plates of scapstone laidrupon a Wall'of the same material, and transverse openings I formed betweenl the desired extent, coming finally to the hot-airchamber I2 at the top, from whence it is taken by pipes to the registers in the usual manner.

In order to deect or turn the iniowing air back and forth through the flues, deliectingplates 13 are arranged as seen in Fig. 2.

The air Which enters the heating-chamber from outside has usually combined with it more or less dust or other foreign matter, which renders such air injurious to health, and the heating of the air in this condition only adds to the difficulty, to avoid which I in. troduce into the passage for cold air a filter, K, composed of an open fibrous material, presenting a wool or woolly surface, sufficiently open to permit the air to pass freely through, but the Woolly fibers retain all the dust or other foreign matter which the air may contain when it comes to the lter, and hence the air which is heated is perfectly pure.

In order to produce perfect combustion, it is essential that more or less atmosphere be directly mingled with the products of combustion above the burning coal. To do this I arrange in the fire-box Wall, preferably in the rear, a due, b, into which the external atmosphere is permitted to flow, and from this ue into the fire-box more or less perforations, 2,

are in ade, through which currents'of air will freely How into the tire-box, as indicated in Fig. 1, there to mingle with the products of, and produce a most perfect, combustion. This ue b is made complete from soapstone, one side of which is perforated, and so as to be laid in the wall, as shown in solid black.

rIo regulate the draft of the fire, a projection or extension, L, is formed on the exit-pipe H', and from the pipe H avertical pipe, L, extends up and connects with the direct draft L2, and thence leads to the chimney. The direct draft- L2 is provided with a damper, l, by which to' turn the draft through the circuitous flue to the exit H. 0n the extension L a circular grooved iange, N, is formed, and over this a cover, N1, is set, (see Fig. 5,) the flange of the cover setting into the groove in the ring, and to this a chain or cord, N2, is attached, by which the cover Nl may be suspended above the ring, as denoted in broken lines. Thus suspended, an opening is formed into the draft-line, and through this cold air will rush to the fine and check the draft, according to the quantity of air admitted; but when closed, the check ceases, and the draft is unobstructed. The groove in the ring is filled with oil or other suitable liquid, .so that when the flange rests therein the opening will be perfectly closed. Between the outlet H and the check a partition, M, is arranged, extending up into the lvertical pipe a short distance, so as to form, as it were, two flues,. both opening into the main due, whereby the possibility of the escape of gas from the furnace through the check When opened is prevented.

I do not wish to be understood as claiming any of the elements shown in the accompanying illustration, except as hereinafter specied.

do not Wish to be understood as broadly claiming openings into the tire-box for the admission ot' air above the fire, as such, I am aware, is not new..

I claim- 1. In combination withl the principal door F of the opening F, the auxiliary door G, constructed to leave a space beneath it, and substantially flush with the surface of the grate, as and for the purpose described.

2.. In combination with the exit-flue of a furnace, the grooved ring N outside the said flue, and the ange-cover N1, substantially as and for the purpose described.

3. In combination with the exit-due H of a furnace, and the check, consisting of the ring N and cover N1, the intermediate partition M, substantially as and for the purpose 'described.

. SIDNEY SMITH. Witnesses: JOHN E. EARLE, CLARA BROUGHTON. 

